docs: def hijack_attr(self, attr_name):
          """Hijack an attribute on the target object.
  
          Updates the underlying class and delegating the call to the instance.
          This allows specially-handled attributes like __call__, __enter__,
          and __exit__ to be mocked on a per-instance basis.
  
          :param str attr_name: the name of the attribute to hijack
          """
          if not self._original_attr(attr_name):
              setattr(
                  self.obj.__class__,
                  attr_name,
                  _proxy_class_method_to_instance(
                      getattr(self.obj.__class__, attr_name, None), attr_name
                  ),
              )